Car stalled and will not restart HELP!

[newsh]

If you can see the alarm control unit, pull the big multipin connector off and check the pins for discolouration.

[montez]

checked the control unit and could not see any discolouration, or any smell of burning. I have had no issues from the immobiliser before and it appears to be working, I will try bypassing where the immob joins the wire to the fuel pump to try and eliminate it.

[newsh]

Well the other place you could be getting a high impedance is in the FP relay.

[montez]

did the fuel pump relay mod and the led is not coming on, will crack open the dizzy next

[S2central.net]

Don't open the dizzy yet... Monitor the 'BS' pin - terminal 47/T on the FP relay to see what it does when you crank over... The ECU might be trying to activate the relay, but if its faulty then it wont go.

The other TEMPORARY trick is to just remove the FP relay cover and tape the contacts closed (30 to 87 and 87a).

If the 'BS' pin is not being pulled to 0V by the ECU then it isnt happy with the RPM sensor input.

You should also check to see if you are getting G40 pulse with an LED.... Maybe the 3B needs this as well to activate fuel pump but I doubt it.

Get a 5V LED and connect across pins 2 (anode) and 3 (cathode) on the plug by teasing back the insulation. When cranking you should see the LED blink OFF every other crank revolution.

[montez]

dizzy is spinning with the car rocking back and forward in 2nd gear so I am guessing it is not the plastic gear

[S2central.net]

PLEASE read post #35.

[montez]

pins do not move when car is cranking, if they are pressed down the fuel pump kicks in and you can here the fuel going to the rail. Car will not start with fp relay pressed down.

[S2central.net]

I would say G28 - the rpm sensor is suspect then. A scope is needed to test properly. I did start work on a cheap cheerful tester for exactly this scenario but it's not ready yet.

[montez]

do you not think this would throw a fault code? and would it stop both fuel and spark?

[S2central.net]

You have the fault code 00513 - that is RPM sensor - but any non running engine gives that... and yes it will stop fuel and spark if it is missing.

[montez]

Is the only way to test it with an oscilloscope?

[S2central.net]

Yes - unless you have some zener diodes, schmitt triggers, a spare LED and some stripboard to build a G28 signal tester. If you send me your address by PM I will post you a G40 tester that you can borrow for a while... Could be some time before I have the G28 tester working - just not had enough time to work on it.

[UrS4boy]

Here is a bit of a flyer (but it could be the answer): Have you checked to see if your flywheel still has the reference pin attached? (See below). This can be seen through the flywheel viewing "port" on the intake side of the engine, at the transmission bell housing.

Link to G4 crank position sensor info:

http://forums.quattroworld.com/s4s6/msgs/20986.phtml

Link to G4 reference pin location info (some of which came from here):

http://forums.quattroworld.com/s4s6/msgs/51259.phtml

[S2central.net]

Good thinking actually - the G4 tester is trickier again to make by the way - but lack of signal from it could indeed be the missing pin routine. Forgot about that one.